This final episode takes us to Iceland. Yet it is in Oxford, among students of the Tolkien Society, that the answers to the long search for the Hobbits lie. What if the Hobbits were born entirely from Tolkien's imagination? And what if they were purely and simply a projection of human beings, with their weaknesses and faults - and their capacity to change the world?

John Howe travels to Germany, the birthplace of the legend of the Niebelungen or the "Gold of the Rhine". There he meets Canadian writer David Day, the author of several works on Tolkien. Will they discover the origins of the Hobbits in this legend, which is full of dwarfs, dragons and a magic ring?

Storyteller Nicolas Mezzalira tells him about the birth of King Arthur and then about the origins of the Knights of the Round Table and the Quest for the Holy Grail, and Professor Leo Garruthers highlights the links between these legends and the Fellowship of the Ring in The Lord of the Rings. For John Howe, this episode is also an opportunity to examine the links between legend and history.

Tolkien took his inspiration from European legends. The first stage of our quest for the sources of the imaginary world takes us to the forest of Brocéliane. Nicolas Mezzalira reveals the legend of Merlin: his birth, romance with the Lady of the Lake, and his first prophecy. The numerous resemblances to the character of the magician Gandalf reveal the extent of Tolkien's force and originality.

In New Zealand, John Howe takes us on an exclusive tour of a film set, which has since been destroyed. In the United Kingdom, Professor Leo Carruthers reveals that the writer Tolkien was also a professor, and an expert on European legends. We must look to these legends for his sources of inspiration. Perhaps they could tell us where the mysterious Hobbits come from.